What's the difference of two Zener diode series (MMBZ52 and BZX84)?

[Rabbitoose]

Hi,

I'm a newbie.
I found the two series of Zener diodes are very similar and looks can be replaceable to each other,  so I wonder why the manufactor made both of them.

They are similar in the following features (onsemi for example):
1. SOT-23 package
2. BZX84 has both 5% tolerance and 2%, but MMBZ52 has only 5% (?), but currently 5% is enough to me.
3. Zener voltage range, MMBZ52 is 2.4V-91V, BZX84 is 2.4V-75V, not a big difference.
4. same ESD rating
5. different IZK (IZT) current? There is not much about it in the datasheet.
6. different impedance, also has no big difference.
7. BZX84 has part type of 6V Zener voltage, but MMBZ52 has no.
8. Power dissipation, MMBZ52 225mW, BZX84 250mW.

I usually use Zener diodes to protect MOSFET, etc., so I feel both series can be used, but now I can't decide which series to buy.

Is there a historic reason, or American/European naming convention, or different qualified standards?

Can anybody help me out?
Thank you!

[Tomorokoshi]

Different historical series by different manufacturers that over time, due to cloning, mergers, spinoffs, etc. show up as similar but not identical parts. Which manufacturer are you reviewing that makes both? Do you have links to datasheets?

[Rabbitoose]

Different historical series by different manufacturers that over time, due to cloning, mergers, spinoffs, etc. show up as similar but not identical parts. Which manufacturer are you reviewing that makes both? Do you have links to datasheets?

Thank you.

Onsemi BZX84: 250 mW; Zener Diode Voltage Regulator
https://www.onsemi.com/products/discrete-power-modules/zener-diodes/bzx84

Onsem MMBZ52: 225 mW; 5% Zener Diode Voltage Regulator
https://www.onsemi.com/products/discrete-power-modules/zener-diodes/mmbz52

[Tomorokoshi]

Different historical series by different manufacturers that over time, due to cloning, mergers, spinoffs, etc. show up as similar but not identical parts. Which manufacturer are you reviewing that makes both? Do you have links to datasheets?

Thank you.

Onsemi BZX84: 250 mW; Zener Diode Voltage Regulator
https://www.onsemi.com/products/discrete-power-modules/zener-diodes/bzx84

Onsem MMBZ52: 225 mW; 5% Zener Diode Voltage Regulator
https://www.onsemi.com/products/discrete-power-modules/zener-diodes/mmbz52

The MMBZ52 series is an old Fairchild line, which is now part of onsemi. Motorola had both the MMBZ52 and BZX84 lines since at least 1994. Either is probably fine in your application. It seems the BZX84 series is more completely defined. You may need to test both in your application to determine the best performance.

[Rabbitoose]

The MMBZ52 series is an old Fairchild line, which is now part of onsemi. Motorola had both the MMBZ52 and BZX84 lines since at least 1994. Either is probably fine in your application. It seems the BZX84 series is more completely defined. You may need to test both in your application to determine the best performance.

Thank you for the accurate information.
I often get confused because I know little about the history of the electronics industry.
Your answers have given me a clear direction.